China riot police seal off city centre after smog protesters put masks on statues

Clampdown in Chengdu after protesters place masks on statues in anger at air pollution choking the city

An environmental protest in China was aggressively put down at the weekend, with a large police presence continuing for days to prevent further demonstrations in an unusually heavy-handed response.

The protests started after the south-western city of Chengdu was shrouded in thick smog, with some residents placing pollution masks on statues. An unknown number were taken away by police, with security forces in riot gear seen in the city's downtown shopping area.